Question

Which of the following plant diseases is/are caused by bacteria?

• A. Angular leaf spot of cotton
• B. Citrus canker
• C. Apple scab
• D. Leaf curl of papaya

Hint:

Bacterial plant diseases like citrus canker and angular leaf spot of cotton can be controlled using bactericides or by improving plant resistance.

Answer 1

The Correct Option is A, B

Step 1: Understanding plant diseases caused by bacteria.
Bacterial plant diseases are caused by various bacterial species. In this case:
- Angular leaf spot of cotton is caused by the bacterium Xanthomonas campestris and is characterized by angular lesions on the leaves of cotton plants.
- Citrus canker is caused by Xanthomonas axonopodis and affects citrus plants, leading to lesions on leaves, stems, and fruit.

Step 2: Analyzing the options.
- (A) Angular leaf spot of cotton is caused by bacteria.
- (B) Citrus canker is also caused by bacteria.
- (C) Apple scab is caused by a fungus (Venturia inaequalis), not a bacterium.
- (D) Leaf curl of papaya is caused by a virus, not a bacterium.

Step 3: Conclusion.
The correct answers are (A) and (B), as both are bacterial plant diseases.